Deleting defaults when using Transaction Import

I am trying to bulk create shipping addresses on screen 08.262.00 using Transaction Import.  I have been working with a test file of about 10 customers on a test database and I have been able to get my import to work without errors BUT there is something happening that I would rather not happen.

The TaxID/TaxIDs that are setup as the default for the customer are automatically populated when I import the new shipping addresses.  Is there a way to get TI to ignore the defaults and leave those fields blank if they are not specified in the datafile?  What I need to accomplish is to import the new addresses without ANY TaxIDs as the project I am working on has to do with creating a new shipping address for every customer that doesn't have any taxes applied.  I am using the intelligent macro for the above listed screen.